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NIH Record - National Institutes of Health

Elevated Blood Pressure in First Trimester Is Risky in Pregnancy

Nurse checks woman's blood pressure.

Elevated blood pressure in the first trimester of pregnancy raises the chances of a high blood pressure disorder of pregnancy.

Photo: wavebreakmedia/getty

Elevated blood pressure in the first trimester of pregnancy, or an increase in blood pressure between the first and second trimesters, raises the chances of a high blood pressure disorder of pregnancy, according to a study funded by NICHD.

The study was led by Dr. Alisse Hauspurg of the University of Pittsburgh School of Medicine and appears in the American Journal of Obstetrics and Gynecology.

The researchers sought to determine how revisions in guidelines for blood pressure in non-pregnant adults might apply to pregnant women. The results suggest that blood pressure readings lower than those traditionally used to identify women as having high blood pressure may indicate a higher risk for a hypertensive disorder of pregnancy, such as gestational high blood pressure, which develops after the 20th week of pregnancy, and preeclampsia, or high blood pressure and protein in the urine. Both conditions increase the risk for stroke in the mother and for stillbirth, preterm birth and low birth weight. Preeclampsia also increases the risk for eclampsia—life-threatening seizures for the mother.

The researchers analyzed data from Monitoring Mothers-to-Be, a study that sought to identify risks for birth and pregnancy complications in first-time mothers. For roughly 8,900 women, researchers compared blood pressure readings in the first and second trimesters of pregnancy to blood pressure status in the remainder of pregnancy. None of the women had stage 2 high blood pressure (140/90 mmHg or higher) at the time they entered the study.

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